The maintenance of sperm morphology and motility to increase the success rate of artificial insemination is known in the art, and is e.g. described in WO2004053465A2. In this document a method and device for assaying sperm motility in a forward direction and density of active sperm in a semen sample are described. The device includes a microfluidics structure having a sample reservoir, a downstream collection region and a microchannel extending there between. The microchannel is dimensioned to confine sample sperm to single-direction movement within the channel, such that sperm in a semen sample placed in the sample reservoir enter and migrate along the microchannel toward and into the collection region. Also included is a detector for detecting the presence of labeled sperm in the microchannel or collection region, and an electronics unit operatively connected to the detector for (i) receiving detector signals, (ii) based on the detector signals received, determining sperm motility and density in the sperm sample, and (iii) displaying information related to sperm motility and density.
EP2508253A1 describes a channel device including a nano-size channel through which single molecule flows, at least one electrode pair arranged near the nano-size channel, and an AC power source that applies an AC voltage to the electrodes. This channel device is useful for identifying molecules one by one. Furthermore, a channel device is described including a nano-size channel through which single molecule flows, a branching portion, and a plurality of branching channels, wherein (i) an electrode pair is arranged near the nano-size channel so as to sandwich the nano-size channel between the electrodes, or (ii) one electrode of the electrode pair is located near the nano-size channel, whereas the other is arranged near the branching channels. This channel device is useful for separating single molecule. The channel device achieves identification or separation at an accuracy of 100% in principle. A sample treatment apparatus according to inventors includes a channel device, a measurement section, and an arithmetic processing section. The measurement section applies a voltage (DC or AC) to between electrodes of an electrode pair installed in the nano-size channel, and measures an electric signal when single molecule passes between the electrodes to identify the molecule.
EP2211164 A1 describes that the electrical properties of particle solutions can be investigated on a single particle basis by using micro fluidic channels. The impedance can be measured across the channel using at least one pair of conductive electrodes, at least one electrode of a pair being a fingered electrode having a plurality of fingers. The pattern of fingered electrodes creates a longer and more complicated measurement signal shape which leads to a significant improvement of measurement sensitivity. An application for the proposed technology is to significantly improve the measurement sensitivity of impedance measurements on blood cells, leading to a better differentiation between different types of white blood cells. Better measurement sensitivity also enables the measurement of smaller particles and higher throughput.
US2005/0118705 A1 describes apparatus and methods for performing microanalysis of particles using a microelectrical-mechanical system (MEMS) chip to electrically interrogate the particles. The MEMS chip is typically manufactured using known lithographic micromachining techniques, employed for example, in the semiconductor industry. A substrate carries a plurality of microelectrodes disposed in a detection zone and spaced apart along an axis of a microchannel. The microchannel is sized in cross-section to cause particles carried by a fluid to move past the electrodes in single file. Impedance is measured between one or more pairs of electrodes to determine the presence of a particle in the detection zone.
US2013/0256197 A1 describes a flow channel device that includes a flow channel in which a fluid containing a particle flows, a plurality of branch channels branched from the flow channel, and an electrode unit. The electrode unit includes a first electrode having a first area and a second electrode having a second area different from the first area, and is configured to form a guide electrical field in the flow channel, which guides the particle to a predetermined branch channel out of the plurality of branch channels. The second electrode is opposed to the first electrode so that the flow channel is sandwiched between the first electrode and the second electrode.
US2014/0248621 A1 describes microfluidic devices and methods that use cells such as cancer cells, stem cells, blood cells for preprocessing, sorting for various biodiagnostics or therapeutical applications. Microfluidics electrical sensing such as measurement of field potential or current and phenomena such as immiscible fluidics, inertial fluidics are used as the basis for cell and molecular processing (e.g., characterizing, sorting, isolation, processing, amplification) of different particles, chemical compositions or biospecies (e.g., different cells, cells containing different substances, different particles, different biochemical compositions, proteins, enzymes etc.). Specifically the document describes a few sorting schemes for stem cells, whole blood and circulating tumor cells and also extracting serum from whole blood.
Segerink et al. describe in “On-chip determination of spermatozoa concentration using electrical impedance measurements” Lab on a Chip vol. 10 (8), (2010) a microfluidic chip to determine the concentration of spermatozoa in semen. For the method, a microchannel with a planar electrode pair that allows the detection of spermatozoa passing the electrodes using electrical impedance measurements. It is further described that cells other than spermatozoa in semen also cause a change in impedance when passing the electrodes, interfering with the spermatozoa count. The change in electrical impedance is related to the size of cells passing the electrodes, allowing distinguishing between spermatozoa and HL-60 cells suspended in washing medium or polystyrene beads.